/**
 *    Copyright (C) 2019-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once

#include "mongo/base/string_data.h"
#include "mongo/bson/bsonelement.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/util/modules.h"

#include <boost/optional.hpp>

namespace mongo {

/**
 * Parsed MapReduce Global variable scope.
 */
class MapReduceGlobalVariableScope {
public:
    static MapReduceGlobalVariableScope parseFromBSON(const BSONElement& element) {
        if (element.type() == BSONType::null) {
            return MapReduceGlobalVariableScope();
        }
        uassert(
            ErrorCodes::BadValue, "'scope' must be an object", element.type() == BSONType::object);
        return MapReduceGlobalVariableScope(element.embeddedObject());
    }

    MapReduceGlobalVariableScope() = default;
    MapReduceGlobalVariableScope(const BSONObj& obj) : obj(boost::make_optional(obj.getOwned())) {}

    void serializeToBSON(StringData fieldName, BSONObjBuilder* builder) const {
        if (obj == boost::none) {
            builder->append(fieldName, "null");
        }
        builder->append(fieldName, obj.get());
    }

    boost::optional<BSONObj> getObj() const {
        return obj;
    }

private:
    // Initializers for global variables. These will be directly executed as Javascript. This is
    // left as a BSONObj for that API.
    boost::optional<BSONObj> obj;
};

}  // namespace mongo
